Initiation and promotion of endochondral bone formation by bone morphogenetic proteins: Potential implications for avian tibial dyschondroplasia

The initiation and promotion of bone morphogenesis is regulated by bone mor phogenetic proteins. Morphogenesis of the skeleton is the developmental cas cade of pattern formation, establishment of mirror-image bilateral symmetry , initiation and promotion of endochondral bone differentiation, and growth culminating in functional weight bearing. implantation of demineralized bo ne matrix initiates a developmental cascade of endochondral bone formation that is reminiscent of the sequential bone morphogenesis in the limb bud in the embryo. The inductive agents in the demineralized bone matrix were ide ntified, isolated and cloned, and demonstrated to be bone morphogenetic pro teins (BMP). The BMP have been implicated in the pattern formation, differe ntiation, and regeneration of bone. Because there is a persistent defect in endochondral bone formation in the epiphysed growth plate in tibial dyscho ndroplasia in poultry, it is likely that BMP signaling mechanisms may be im paired.